<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <script>
        var a =["ni","shi"];
        var b =["er","bi"];
        var c = a.concat(b); //concat是数组合并。
       /* for(var i=0;i< c.length;i++){
            alert(c[i])
        }*/
        for(var j= c.length-1;j>=0;j--){
            alert(c[j])
        }
    </script>
</body>
</html>